1. Field of the Invention
The present invention relates to devices, systems, and methods for analyzing the stability of snow and for forecasting avalanches.
2. Background
An avalanche is the rapid movement of a material down sloped terrain. Most avalanches are primarily composed of snow; however, avalanches may also contain ice, rock, and soil. In general, avalanches occur after snow has been deposited, either by precipitation or by wind, on hills or mountains. When appropriate conditions occur, the snow is suddenly released and the downward rushing snow can release an exceptional amount of energy.
Avalanches have caused a tremendous amount of deaths, injuries, and damage to property. Statistics indicate that the devastating impact of avalanches is rapidly increasing. As the popularity of mountain and winter sports increases, such as backcountry skiing and snow boarding, mountain climbing, and snowmobiling, and the number of people living in or traveling through mountainous area increases, avalanches are killing and injuring more people and destroying more real and personal property.
To date, most advances in avalanche technology have been intended to help those people who have become trapped in avalanches. For example, U.S. Pat. No. 6,484,021 issued to Hereford et al. discloses an example of a radio transceiver that is intended to locate a buried victim. U.S. Pat. No. 5,490,501 issued to Crowley discloses a breathing device that helps an avalanche victim breath when buried in snow. However, there have been very few practical advances in the area of avalanche forecasting. If avalanches could be more easily and accurately forecast, many deaths and injuries could be prevented and the cost of preventing avalanche accidents could be greatly reduced.
There are a number of methods known in the art for determining the risk or likelihood of an avalanche occurring. These techniques include the following structural or physical tests for determining the stability of snow in a particular area: ski pole, hand shear, step, jump, ski traverse, tilt board, cornice, snow pit, compression, shovel shear, ski shear, loaded column, pat, Rutschblock, Rutschkiel, and stuffblock. For example, the Rutschblock and shovel shear tests involve digging a hole in the snow and, crudely, jumping up and down, or pushing the snow sideways with a shovel to judge its strength. These tests are currently widely used to identify weak snow structures.
However, these tests do not measure important variables affecting the likelihood of an avalanche. Although the structural strength of a block of snow can, in some situations, indicate an avalanche risk, the occurrence of an avalanche may depend more on other variables that are not analyzed by these tests. Studies show that the risk of an avalanche is affected by many different factors. Temperature, slope, density, size and shape of snow crystals, hardness, relative humidity, radiation, water content, and other metrological factors can all have a significant influence on avalanche risk. In many cases, these influences increase the probability of an avalanche, so that an area may not be safe even though commonly used tests indicate that it is.
Another problem associated with commonly used tests is that they are difficult and time consuming to perform. A Rutschblock test, for instance, may require a person to exert a significant amount of energy to dig out a pit and perform the test. If a backcountry skier is performing the test, it may be necessary for the skier to put his equipment (skis and backpack) on and off several times. Because of this, most people do not perform the test as much as they should. Furthermore, many people are not sufficiently trained or experienced enough to interpret the results of the test. What has long been needed is a device, system, and method for efficiently and accurately forecasting avalanches.